1. Field of the Invention
The present invention relates to an image processor and an image processing method for applying image processing to image data.
2. Description of Related Art
In recent years, photo processors in which so-called digital exposure methods are adopted, are coming to be widely used. In such a digital exposure method, an image can be formed by exposing a photographic printing paper to light that has been modulated on the basis of digital image data. By adopting the digital exposure method, various kinds of image processes, such as color correction, density correction, and sharpness processing, can be performed in a high degree of freedom. In addition, rapid reprint processing becomes possible. Further, a high-quality print superior in color reproducibility, density reproducibility, and resolution, can be obtained.
In a photo processor, there is a case wherein a large-sized image is formed on the basis of small-sized image data including therein pixels less than the large-sized image. Generally in this case, after image processing is applied to the small-sized image data, the small-sized image data is enlarged so that the number of pixels included in the small-sized image data is increased so as to correspond to the number of pixels of the image of the final print size, for example, as disclosed in JP-A-2002-199208.
Image processing to be applied to such image data may include cross filter processing for blurring light of each portion of the image high in brightness into a cross shape. By applying cross filter processing to the image data, high artistry and a special visual effect can be obtained, and realistic sensation and impact can be given to the photographic image.
However, in the case that the number of pixels included in small-sized image data as the original image data for enlargement processing, considerably differs from the number of pixels included in enlarged large-sized image data, a problem arises wherein the effect of cross filter processing applied to the small-sized image data before enlargement processing is performed, may reduce in an image formed on the basis of the enlarged large-sized image data. That is, in the case that the magnification of enlargement is too high, there is required a large number of additional pixels to be interpolated to compensate the difference between the number of pixels of the large-sized image data and the number of pixels of the small-sized image data. As a result, cross filter processing brings about conspicuous edges, and this reduces the effect of cross filter processing. To solve the problem, a measure is thinkable wherein the order of image processing and enlargement processing is changed so that cross filter processing is applied to the large-sized image data after the small-sized image data is enlarged into the large-sized image data. In this case, however, the rate of cross filter processing remarkably lowers though the effect of cross filter processing scarcely reduces.